CaptainSS1

Just got a New (re-manufactured) LS6 installed. Motor has new everything. We put a 224/228/114 cam, UDP, Kooks Headers, etc. Dyno'd 412/400 rw on a 90 degree day, humid - thru a 12 bolt Moser.

Anyway, on start-up (about 20 seconds after start-up) I am getting smoke from the tail pipes. Stops after it warms up and never smokes again. No smoke while driving, hard acceleration and sudden deceleration, shifts, re-starts throughout the day - nothing.

Any thoughts? Could it be enrichment in the programming, condensation....

Coolant is fine and oil level on the dipstick is fine after about 300 miles since the install.

robertbartsch

PVC sucking oil into the intake from the valve cover?

Do you have a oil PVC catch can installed? If not, make one from PVC pipe from Depo. Bigger is always better. Mine is 2 inches in diameter and 6 inches long.

CaptainSS1

I greatly appreciate you taking the time to make that suggestion. In your estimation, would that (if it was that) cause the problem? It is very predictable how it occurs. It is only on cold start (first start of the morning after sitting) doesn't happen the rest of the day. It comes on about 15-20 seconds after the start. Starts slowly and gets quite smokey until the temp comes up and then it subsides.
Doesn't occur during driving.

angelR

iTrader: (7)

Sounds like possibly valve stems with that description.

99blancoSS

iTrader: (115)

Does it do it on startup all the time, or just after you started it up after installing.
There is a lot of lube in there when they build a motor and it needs to burn off.

CaptainSS1

Only on start-up after sitting. Which has only been maybe 3 times since getting it back from the builder. Subsequent start-ups during the day or during driving - no smoke.

Approx. how long does it take to get rid of the build lube?

99blancoSS

iTrader: (115)

maybe 100 miles or so. Mine smoked for a bit. What color smoke are you getting now?

1BadDime

iTrader: (26)

If its cool outside where you live, It could be condensation in the exhaust system. this will only happen if you start your vehicle after it has been sitting for a while and has completely cooled down. When you start it, the exhaust warms up and the cool exhaust piping starts to condensate, and the condensation comes out the tail pipes untill it warms up completely.

Happens up here in Canada when it gets cold.

CaptainSS1

I'm bad at colors of smoke, I'd say gray/white.

angelR

iTrader: (7)

Sounding to me even more like the stem seals. Sits for a while and smokes on startup....classic description. Hey at least it's a fairly cheap and easy fix.

CaptainSS1

ALL aspects of the valve train are brand new. I am leaning in the direction of condensation. Also, because the last motor "let go" I think there may be coolant in the exhaust. There was coolant in the intake manifold and cylinders of the last motor.
IF a quantity of that coolant got into the exhaust, I imagine that could have some residual effect.

NastySSoo

I agree with angelR. Classic valve stem seals in heads! They leak down overnight and then burns off when you start it!

Paul

99blancoSS

iTrader: (115)

grey white sounds like condensation, blue is oil black is fuel, a new valvetrain will have assembly/grease lube on the valve stems to burn off. A classic valve seal issue is an old chevy 350 that smokes blue smoke at startup then goes away. I dont think thats his issue. grey white is not oil smoke from valve seals

xBROKEx

iTrader: (7)

does it smell like anything?

CaptainSS1

No, the smoke actually smells like nothing.

99blancoSS

iTrader: (115)

condensation

CaptainSS1

Thanks to you and all who chimed in, it is always a big help to have the opinions of others who have our cars.....Danke